Cross-platform COVID-19 contact tracing with Apple and Google: users, privacy, metrics

Apple and Google are building a contact tracing product together to help slow the spread of COVID-19 and get the world past the pandemic. You are the product manager working with engineers from both companies. How would you design it? Walk through whom the product serves, what it does and how it works at a high level, and how you would judge whether it helps. ```hint Usefulness depends on who turns it on Tracing helps only if enough people turn the feature on and keep it on, and if alerts reach contacts sooner than manual tracing would. Let those two needs drive what data you collect, where you keep it and who can see it. ``` ### Clarifying Questions - Are the two companies shipping one app of their own, or a capability built into their operating systems that public health authorities' apps use? - Should health authorities learn who was exposed, or only that alerts went out? - What confirms a diagnosis before it can trigger alerts: a verified test result, or self-reported symptoms? - Is the launch global from day one, given that countries differ on privacy law and on how they run contact tracing? ### What a Strong Answer Covers - The stakeholders and what each needs: people who test positive, their contacts, the wider public who must choose to take part, public health authorities, and the two platform owners. - A concrete high-level mechanism for detecting close contacts across Android and iOS and alerting them, with the choice of signal justified against alternatives. - An explicit position on where data lives, who can see it and how consent works, and how that position affects adoption. - How accuracy and abuse are handled: false alarms, missed contacts and fake reports of a positive result. - Success metrics tied to slowing transmission, with guardrails for privacy, battery life and trust, and a plan for ending the product. ### Follow-up Questions - Only a fifth of the population turns the feature on. Is it still worth running, and what would you change? - A government asks for the identities and locations of exposed people to enforce quarantine. How do you respond? - How would you decide when to switch the feature off?